Radiofrequency transformer



Jan. 11 1927.

C. PF'ANSTIEHL RADIO FREQUENCY TRANSFORMER Filed July 17 1925 2Sheets-$heet 1 c. PFANSTIEHL RADIO FREQUENCY TRANSFORMER Jan.

Filed July 17, 1925 2 Sheets-Sheet 2 Patented Jan. 11, 1927.

UNITED STATES PATENT OFFICE.

CARL PFANSTIEHL, OF HIGHLAND PARK, ILLINOIS, ASSIGNOR TO PFANSTIEHLRADIO COMPANY, A CORPORATION OF ILLINOIS.

RADIOFREQUENCY TRANSFORMER.

Application filed July 17, 1925.

This invention relates to radio-frequency transformers of the toroidaltype and is fully described in the following specification and shown inthe accompanying drawings, in which Figure 1 is a front elevation of thetransformer embodying the invention;

Fig. 2 is a similar view of the supporting means with the coil unitsremoved;

Fig. 3 is a partial section on the line 3 of Fig. 1, showing the coil onits supporting P Fig. 4 is a diagrammatic transverse section through thecoil;

Fig. 5 is a developed view of the preferred form of one of the coilunits;

Fig. 6 is a similar view of a modifiet form of the same; and

F ig. 7 is a diagrammatic view similar to Fig. 1, showing the wiringdiagram of the coil units assembled in a coil.

The embodiment illustrated comprises a coil of the toroidal or doughnut,type herein, as shown in Figs. 1 and 4. Each coil is made up of a seriesof coil units 10, each coil unit having an open center 11. and the coilsarranged about a common center and so wired as to simultaneously sendelectromagnetic impulses through the coils in the same direction. Owingto its nearly closed formation, electro-magnetic lines of forcegenerated within the coil will have little tendency to stray beyond theconfines of the coil.

Each coil unit 10, as shown in Figs. 4 and 5, is made up by winding asuitable insulated wire about a core (not shown) the shape of the center11 and having a series of pins over which the wire is wound back andforth, passing over one pin, under the next, and over the next, etc.

In order to get as uniform a distribution of these wires about the outeredge of the coil as may be possible, the wire in its passage about thecoil is carried first about the Y-shaped branch 10, the next .timearound about 10 the next around about 10 etc., with a result that theouter portion of each coil unit is made somewhat fanshaped, as shown inFigs. 1 and 5. Thus, the relatively straight center portion 10 is leftquite fiat so as to occupy relatively little space at the center of thecompleted coil, as shown in Fig. 1, while the Y-shaped branches 10 and10 are spread out so as Serial No. 44,218.

to be uniformly distributed about the outer periphery through the coil,as shown in Fig. 1.

For convenience in mounting, the coils 10, twelve in number, one foreach pin 14:, are placed about a central spool 12 which, if desired, maybe secured to the plate 13, or other object, on which the coil is to bemounted. Ends 14, as shown in Figs. 1 and 3 are secured in the plate 13and fit snugly into openings 15 in the coils 10.

In Fig. 7 is shown a diagram of connections in which the primary coil 16is connected to binding posts, or the like, 17 and 18. The secondarycoils 19, 20, 21, 22 and 23 are alternately connected across from oneside of thetransformerto the other so as to bring the last coil 2-1 asfar as possible from the primary coil 16 so that the potential generatedin the secondary shall be highest at the binding post 25 which isconnected to the grid of the audion tube while the binding post 26connected to one end of the coil 19 will have the lowest potential andwill be connected to the filament of the same tube.

In Fig. 6 is shown a mocified form of the coil in which the outerportion 27 is wound on larger pins than the central portion 27, With aresult that the outer turns of the coil are spread out more than thoseof the cen ter for the reasons heretofore stated.

\Vhile I have shown and described but a single embodiment of thisinvention, it is to be understood that it is capable of manymodifications. Changes therefore in the construction and arrangement maybe made which do not depart from the spirit and scope of the inventionas disclosed in the appended claims.

\Vhat I regard as new, and desire to secure by Letters Patent, is:

1. A radio-frequency transformer unit comp 'ising a coil formed about ahollow center, the strands crossing a plane of the coil in wave form sothat adjacent strands cross each other at intervals and lie on oppositesides of said planes, the strands in one portion of said coil being morewidely separated laterally than on the other.

2. A radio-frequency transformer unit comprising a D-shaped coil, thestrands crossing a plane of the coil in wave form so that adjacentstrands cross each other at intervals and lie on opposite sides of saidplane, the strands on the rounded portion of said D-shaped coil beingmore Widely separated laterally than on the relatively straight side.

3. A radio-i uency transi'ormer unit comprising a coil which has arelatively flat portion, the coil on the opposite portion being dividedinto iateraiiy spaced sections, each section being made up of adjacentstrands of wave form cr ssing each other at intervals.

i. A radio-frequency transformer unitcomprising a coil which has arelatively tiat portion, the coil on the opposite portion being dividedinto l: erail spaced sections, each section being made up of adjacentstrands of Wave form crossing each other at intervals, the strands ofthe divergin tions being more widely s parated than in said straightportion.

5. A radio-frequency transformer having a primary and a secondary, thesecondary being composed of a series of units according to claim 1,these units being so Wired thatthe low voltage side of said secondary isadjacent the primary and the high voltage side opposite said primary.

6. A radio-frequency transformer having a primary and a secondary thesecondary being composed of a series of units according to claim 3,these units being so \vired that the low voltage side of said secondaryis adjacent the primary and the high voltage side opposite said primary.

7. A radio-frequency transformer having a primary and a secondary, thesecondary being composed of a series oif units according to claim lthese units being so \vired that the low voltage side of said secondaryis adjacent the primary and the high voltage side opposite said primary.

8. A radio-frequency transformer having a primary and a secondary, thesecondary being composed of series of units accord ing to claim at.

. CARL PFANSTIEHL.

